The inventor of this application has proposed a pipe joint device in another Japanese patent application No. 2002-348868 (Publication No. 2004-183703) before the present invention, which, however, has not been published before the present invention.
The proposed pipe joint device has a ring shape body and first and second retaining portions, which are respectively formed at both axial ends of the ring shape body and projecting radially and inwardly from the axial ends.
The above pipe joint is mounted on a second pipe member, in which the second retaining portions are radially and outwardly deformed (elastically expanded) when the second pipe member is inserted into the pipe joint device. Since the second pipe member has a female joint portion at its forward end, at which an outwardly expanded portion is formed, the pipe joint member is prevented from being removed from the second pipe member.
A first pipe member has a male joint portion at its forward end, at which an outwardly expanded portion is likewise formed. When the male joint portion is inserted into the female joint portion of the second pipe member, the first retaining portions are elastically deformed in a radial and outward direction. The first retaining portions return to initial shape due to elastic force, after the first pipe member has been completely inserted into the second pipe member, so that the first retaining portions are axially brought into contact with the outwardly expanded portion of the first pipe member, to firmly retaining the first pipe member to the second pipe member. Accordingly, an assembling of the first and second pipe members by the pipe joint member can be easily done in the above proposed device.
The inventor of the present invention has, however, found a drawback of the above proposed pipe joint device, when the pipe members will be disassembled. Namely, in the case that the pipe members are disassembled when the fluid (refrigerant) is filled in the pipe members and a high fluid pressure is existing in the pipe members, the pipe members would be rapidly put away from each other due to such a high pressure fluid, and the fluid would be discharged from the pipe members at a dash.